Soft decoding method using LLR conversion table

A method for controlling a non-volatile memory using a decoder, the method comprising:

• reading data stored in the non-volatile memory as a received value;
• converting the received value read from the non-volatile memory to first likelihood information by using a first conversion table for use by the decoder;
• decoding, by the decoder, the first likelihood information;
• outputting a first estimated value with respect to the received value when decoding of the first likelihood information has succeeded, the first estimated value being based on a decoding result of the succeeded decoding;
• aggregating a number of occurrences of a pair of the received value and a second estimated value, when the decoding of the first likelihood information has failed, the second estimated value being generated based on a decoding result of the failed decoding;
• generating a second conversion table based on an aggregation result, when the decoding of the first likelihood information has failed;
• converting the received value to second likelihood information by using the second conversion table for use by the decoder when the second conversion table is generated;
• and
• decoding, by the decoder, the second likelihood information.